#include <bits/stdc++.h> 

using namespace std;


int main() {
    int n, k;
    cin >> n >> k;
    vector<int> cnt(n + 1);
    for (int i = 1; i <= n; ++i) {
        int x;
        cin >> x;
        cnt[x]++;
    }        
    sort(cnt.begin(), cnt.end(), greater<int>());
    int ans = 0;
    for (int i = 0; i <= n; ++i) {
        if (k >= cnt[i]) ans++, k -= cnt[i];
        else if (k) ans++, k = 0;
        else break;
    }
    cout << ans;
    return 0;
}